Internet company Yahoo says it will anonymize some user data within 90 days of its collection. That includes information on the sites users visit, and advertisements they click on.

Meanwhile the Ponemon Institute, a research group that focuses on privacy issues, hasreleased its annual Most Trusted Companies survey. Google fell from its top 20 perch, partly because consumers expressed growing unease with Google’s data collection and retention practices.

Microsoft this week launched another rewards program that pays people for using Live Search, which has failed to make much of a dent in the most popular search engine, Google. The new SearchPerks program – available only to Windows and Internet Explorer users – awards points for using Live Search, which can be redeemed for prizes like music downloads and video games.

John McCain and Barack Obama are engaged in an advertising contest on the Internet, where both are buying up keywords from the likes of Google and Yahoo. Ads for the campaigns appear in search results when surfers search on keywords and phrases like “Iraq war” and “bailout.”